Documentation of physiological parameters and blood
profile in newly born Kajli lambs.

Abstract:

Newly born lambs have to face challenges in a new environment
totally different from that of the uterus. Adaptation to extra-uterine
life involves functional changes with almost each organ and system in
the body undergoing a series of metabolic and anatomical modifications.
Failure to adapt the extra-uterine environment can not only lead to
homeostatic disturbances but also lead to the death of the affected
lambs. Hematological parameters of newly born lambs show variability
that differs between breeds of lambs. The purpose of present study was
to determine homeostatic responses and physiological reference values in
Kajli breed lambs occurring in the neonatal period through changes in
blood profile, respiratory rate, heart rate, live weight and rectal,
scrotal and skin temperatures. For this purpose, sixteen clinically fit
lambs (males = 10 and females = 6) with a mean body weight 6.92 [+ OR -]
0.46 kg were selected. Physiological data of selected parameters of each
Kajli lamb was recorded at three day intervals and hematological
parameters at five days for a period of 30 days. In general, statistical
analysis showed a significant effect of time (p<0.001) on all the
studied physiological and hematological parameters except platelets
counts, white blood cells and hemoglobin concentration. The results
documented in the current study are an addition to existing knowledge of
the physiology of Kajli sheep breed should be helpful in developing
feeding, disease diagnoses and treatment protocols for newborn Kajli
stock. (Key Words : Neonatal Period, Body Temperatures, Heart Rate,
Respiratory Rate, Hematological Parameters, Kajli Lambs)

Newborn lambs are usually threatened by multiple risk factors
particularly to perinatal diseases, disorders of noninfectious aetiology
or by pathological conditions of microbial or parasitic, which may lead
to high rate of mortality due to weak or less developed immune system at
this critical stage of life span (Fragkou et al., 2010). About 10% of
the alive born lambs can die on the day of birth because of different
factors and this indicates death of almost half of all pre-weaning lambs
(Dawyer, 2008). Modification and adjustment of extra-uterine environment
according to the needs of newborn in the first week of life can greatly
reduce the death rate (Nowak et al., 2000; Sawalha et al., 2007).
However, because of differences in breed and species the adaptation
response to the new environment by lambs may differ and evidence does
exist that lambs may fail to cope with the modifications associated with
independent life because of their inability to maintain homeothermy and
establish breathing (Sawalha et al., 2007). In this context, initiation
of regular breathing, modification in lungs and gas exchange, alteration
of the circulatory pattern and regulation of temperature are considered
of vital significance in order to ensure the smooth transition of
newborn from uterine to neonatal life (Leone and Finer, 2006).

Cardio respiratory system undergoes prominent changes in neonatal
period (Knottenbelt et al., 2004) and it can be influenced by season,
day timings, ambient temperature, humidity and exercise (Fahmy, 1994;
Marai et al., 2007). Fetal heart rate also shows variability from low to
high around parturition and then develops typical variability depending
on activity in later life (Desmond et al., 1963). Furthermore,
maintenance of homeothermy during this transition period strongly
supports the well being of lambs, however, failing of this may lead to
increase mortality rate (Dwyer, 2008). In uterus, fetus is completely
adapted to its environment having stable temperature about 0.5[degrees]C
higher than the maternal temperature (Gunn and Gluckman, 1983). Neonatal
lambs are not capable to face cold and heat stress and they show
response to high temperature by change in respiratory rate and irregular
breathing (Symonds et al., 1995).

Birth weight is also an important factor which plays a pivotal role
in the maintenance of body temperature and growth in new life. Lambs
born with light weight (4.1 kg) are known to have a reduced ability to
maintain body temperature as compared to heavier (5.2 kg) lambs (Susic
et al., 2005; Dwyer, 2008). An increase in ambient temperature results
in rise of rectal, skin and scrotal temperatures which could be
different in different seasons and day timings (Yousaf, 1985; Taylor and
Bogart, 1988; Fahmy, 1994). Moreover, birth weight can be influenced by
breed and sex during pregnancy (Buschmann et al., 1993). Low birth
weight lambs, being less energetic and having fewer tissue reserves,
take much time to reach the udder for sucking than heavier lambs (Dwyer
and Morgan, 2006) which results in poor growth. In addition, body weight
and growth rate can also be influenced by an elevated ambient
temperature due to its effect on the metabolism, decreased anabolic and
increased catabolism (Ismail et al., 1995).

Hematological parameters also pass through a series of changes and
are helpful to determine the health and nutritional status of animals
(Gupta et al., 2007). The implication of determining hematological
parameters of domestic animals is well-documented (Obi and Anosa, 1980;
Vihan and Rai, 1987). Documentation of these valuable indices in
neonatal period are helpful to establish a suitable physiological
baseline values for various breeds of sheep that in turn could be
employed in the pragmatic evaluation of the administration practice,
nourishment and diagnosis of health condition in the most critical
period of life. Studies on the blood profile have been conducted mostly
in Africa and some other parts of the globe and these were on adult
animals. The scientific information regarding physiological and
hematological parameters in newborn lambs of Kajli sheep breed is very
limited.

Keeping in view the importance of having physiological reference
values as indicators of dynamic homeostatic processes taking place
during the first 30 days following the birth of a lamb, the present
study, therefore, was undertaken to observe hematological parameters,
body temperatures, respiratory and heart rate and live weight gain to
obtain and document valuable information for neonatal care of Kajli
lambs.

MATERIALS AND METHODS

Study area and animal characteristics

Present study was conducted on Livestock Experiment Station,
Khizarabad, located in district Sargodha (32.08[degrees]N and
72.67[degrees]E), Punjab, Pakistan. This is an agricultural area famous
for citrus fruit production. Climatic conditions of this area are
extreme with the temperature ranging from 5 to 49[degrees]C.

Sheep breed Kajli is inhabitant of this region which is a large
mutton breed having average body weight 45-55 kg. Adult males of this
breed are heavier (>55 kg) than females 45 kg). Annual wool yield per
head is 3 kg and the fiber diameter is 37 |am. Body of the Kajli sheep
is well developed with long pendulous ears, long legs, roman nose and
short tail. Kajli sheep was selected for this study because it has been
proposed that the young animals of this breed perform well in their
natural habitat (Sargodha district) but they do not thrive well when
taken to other parts of the province having similar climatic conditions.

Physiological parameters

Sixteen clinically healthy lambs (10 males and 6 females) were used
in the study which was conducted from mid April to mid May, 2008. All
lambs were housed with their mother during the entire study period and
fed on dam's milk. On the first day of the experiment, mean age was
5 [+ or -] 1.5 days while weight was 6.92 [+ or -] 0.46 kg. For each
lamb different physiological parameters (heart and respiratory rates,
rectal, skin and scrotal temperatures and live weight) were recorded at
a 3-day interval at the same time (8:00 AM) from 5 days post-lambing for
a 30-day period. Body weight was measured with an electronic scale
(Wazan Tech. Pakistan) while heart rate was determined with the help of
heart rate monitor (Kyto Electronic Corporation, China) and respiratory
rate recorded visually using a stopwatch over a 5 min period. Rectal,
skin and scrotal temperatures were recorded using a digital thermometer
(Yancheng Diling Medical Instrument Co., Ltd., China).

Hematological parameters

The blood samples were collected at each five-day interval starting
from day five of neonatal period. Jugular vein was punctured and the
blood placed in vacuitainers containing anticoagulant ethylene diamine
tetra-acetic acid (EDTA) for hematological study. Blood samples were
carried to Al-Shifa Laboratories Faisalabad city (Punjab, Pakistan) on
the same day for haemocytometery and blood chemistry using fully
automatic blood CP analyzer (Nihon Kohden, Japan).

Statistical analyses

Results were presented as mean [+ or -] SD. A one-way repeated
analysis of variance (ANOVA) was used to determine statistical
differences between mean values of the studied parameters in the first
month postpartum. All the measurements were analyzed by generalized
linear model using statistical software Minitab 12.1 (Minitab, 2002).

RESULTS

Live weight

An increase in live weight was noted right from the start of trial
(6.9 [+ or -] 0.4 kg) to the end (10.9 [+ or -] 1.3 kg) with a daily
weight gain of 133 g (Figure 1A). During the last 10 days of the trial,
there was a marked individual variation in live weight of the lambs as
clear from standard deviation bars (Figure 1A). Mean birth weight of
both sexes was almost same but males were slightly heavier (0.46 kg)
than females. Difference in live weight was observed with the increase
in age and it was maximum at 32 days postpartum (range 8.6 kg to 13.7
kg).

[FIGURE 1 OMITTED]

Heart rate

During the 30-day study period, heart rate of lambs decreased from
mean 187.8 [+ or -] 11.1 to 144 [+ or -] 12.5 beats/min (Figure 1B).
This decrease in heart rate was not consistent as it decreased sharply
from 5th to 11th day postpartum followed by an irregular increase and
decrease (p<0.001) again at the end of the trial (Figure 1B).
Differences in heart rate remained unaltered (p>0.05) for the
following postpartum days: 8 vs. 20, 14 vs. 26, 17 vs. 23, and 17 vs.
29. Male animals had slightly higher heart rate than females throughout
the study period.

Respiratory rate

Animals showed an irregular decrease in their respiratory rate from
days 5th to 17th postpartum followed by an uneven increase which was
less than the initial observation (Figure 1C). A significant effect of
time (p<0.001) was noted for both male and female animals while an
insignificant difference (p>0.05) was observed among days 11 vs. 14,
17 and 26 postpartum (Figure 1C).

Temperature

Temperature recorded from three different sites showed a decrease
in mean values (p<0.001), however, rectal temperature remains nearly
constant with slight decrease at the end of trial period (Figure 1D-F).
A marked decrease was observed in mean skin temperature in the last six
days of the trial (Figure 1E) while that also occurred in the last three
days for the scrotal skin temperature (Figure 1F). Reduction in skin
temperature was gradual from the start to the end of trial except on day
20 postpartum but it was not true for scrotal skin for which uneven
decrease was observed (Figure 1E, F).

Hematological parameters

Mean values of PCV, Hb, RBC, WBC, neutrophils, monocytes,
lymphocytes, eosinophils and basophils are shown in Table 1. There was a
significant difference (p<0.05) in the mean values of RBC,
neutrophils, lymphocytes, eosinophils, basophils and monocytes whereas
Hb, platelets and WBC level remained the same (p<0.05) throughout the
trial period (Table 1). Basophil count decreased (p<0.001) from mid
to the end of trial period while a considerable decrease (p<0.001)
was also observed in the mean values of Hb, WBC, monocytes, RBC and
lymphocytes (p<0.01). However, mean values of eosinophils increased
(p<0.001) with the passage of time.

Mean corpuscular elements of Kajli lambs also showed a significant
difference (p<0.001) during the 30 days of postpartum (Table 1). Mean
values of MCV, MCH and MCHC decreased with respect to time but this
reduction was relatively more in mean MCV as compared to others.

DISCUSSION

In the present study, observations on physiological parameters of
lambs were started from day 5 postpartum as rate of lamb mortality
decreases beyond the first week of life (Nowak et al., 2000; Sawalha et
al., 2007). An increase in live weight during neonatal period is a well
established phenomenon which can be influenced by nutrition, high
temperature and diseases (Shelton, 2000; Abdel-Hafez, 2002; Saddiqi et
al., 2010). Linear regression model between live weight and post-natal
days shows a steady increase in live weight with the increase in age of
animals. Piccione et al. (2007) reported an increase of 234 g in live
weight compared to 133 g observed in the present study. This discrepancy
might be due to variation in genetic potential of two breeds as some
breeds are known to have better growth rate than others (Marai et al.,
2007), stress of summer season and management practices (Marai et al.,
2008). Birth weight may be another factor that has direct or indirect
effect on growth rate as vigorous lambs (5.2 kg) compared to weak lambs
(4.1 kg) have better suckling potential (Susic et al., 2005; Dwyer and
Morgan, 2006).

Previously, Piccione et al. (2007) reported a gradual decrease in
heart rate of lambs during the first 30 days of their life whereas, in
the present study, we observed an irregular decrease in heart rate
during the same period. They also observed lower heart rates in contrast
to the findings observed in the present study. These discrepancies might
be due to difference in temperature of the two study areas as change in
ambient temperature is known to influence the heart rate of young
animals (Sleiman and Saab, 1995). All the observations for heart rate
were taken almost at the same time of the day as it is well documented
that heart beat varies following walking, exercising and suckling
processes (Leone and Finer, 2006). Similarly, pulse rate is also
affected by morning and noon timings due to various ambient temperature
peaks (Marai et al., 2007).

We observed a higher respiratory rate in Kajli lambs than reported
by Anderson (1975). In the present study, the variations recorded for
respiratory rate are consistent with previous studies indicating that
this parameter displays homeostatic physiological variability during the
first four weeks postpartum (Davey et al., 1998). Our observations are
in concordance with those of Davey et al. (1998), whereas contrary to
Piccione et al. (2007), where we noted a higher respiratory rate in male
group both at the start and the end of trial but it was not true for
females which showed elevated values only in middle (14 to 20 days
postpartum) of the trial.

With respect to temperature, our findings are in contrast with
those of Bianca and Kunz (1978) showing a better adjustment of Kajli in
relatively high temperature. Skin temperature decreased gradually in
contrast to scrotal temperature (Figure 1E, F). Previosuly, Fahmy (1994)
and Marai et al. (2009) reported an increase in rectal and skin
temperatures with the increase in ambient temperature. Various factors
are responsible for irregular pattern of scrotal skin temperature which
includes humidity and fluctuation in temperature during cloudy days.
Sheep has efficient thermal homeostasis mostly in first month of
postpartum (Piccione et al., 2002) that may be due to low quality
fibrous feedstuffs into protein and other products (Hafez, 1987).
Homeostasis is achieved by evaporation of water by respiratory tract by
panting or sweating involving skin surface (Marai et al., 2007) and at
high temperature via ears and legs. Rectal temperature increases only
when physiological mechanisms of body are non-productive to counteract
the unnecessary heat load. Thermoregulatory process is also influenced
by birth weight and some reports suggest that lighter lambs at birth
have reduced capability to sustain body temperature (Alexander, 1975;
Dwyer, 2008).

A significant decrease in mean cellular counts was observed except
eosinophils. Previously, Mbassa and Poulsen (1991) and Azab and
Abdel-Maksoud (1999) also reported an increase in eosinophil count
during the early neonatal period. In current trial, mean values of RBC
decreased significantly (p<0.001) in first month postpartum in both
male and female flocks and similar findings were documented by Azab and
Abdel-Maksoud (1999). White blood cells of female Kajli lambs showed a
slight increase (p>0.05) during the study period while opposite was
the case in male animals. Mean values of WBC counts at the end of trial
are close to reference haematological values of Girgentana goats (Opara
et al., 2010). A significant increase was noted in mean eosinophil
counts that may be due to allergic response to ecto-or endoparasites
(Buddle et al., 1992). In contrast to the findings of present study,
Azab and Abdel-Maksoud (1999) observed significant reduction in mean
eosinophil count. Mean lymphocytes values showed significant decrease in
female group compared with male. Values of present experiment did not
match with those of Daramola et al. (2005) where male West African Dwarf
goats had higher lymphocyte count compared to the females. Reference
values set for West African Dwarf goats (Opara et al., 2010) were higher
(64.8 [+ or -] 1.7) than Kajli lamb during the same period. Neutrophil
counts remained almost constant with a small decrease in middle of the
trial while mean monocyte counts showed a significant decrease
(p<0.05) which was slightly more in male group. Production of
neutrophils is independent according to body's demand and health of
animals. Breed, temperature and environmental factors also influence
their production (Waziri et al., 2010). Animal sex is also believed to
have a significant effect on neutrophil count (Daramola et al., 2005).
In present study, female had increased neutrophil values in first 15
days postpartum. Similar findings have been reported earlier by Tambuwal
et al. (2002) and Daramola et al. (2005). Monocytes values at day 5
postpartum resembled to the reference values of goat (Opara et al.,
2010) while neutrophils cellular counts of current study were about
twice than noted by Opara et al. (2010). Basophil and platelet counts
showed a considerable reduction (p<0.001) from the start of study to
the end of trial which is in contrast with the previous findings of
Waziri et al. (2010).

Values of Hb are adjusted according to oxygen carrying capacity of
the blood and hence its level can vary according to different age groups
(Tambuwal et al., 2002). In the present study, a slight decrease in Hb
concentration was observed but overall difference with respect to time
was not significant (p<0.05) but significant (p<0.001) when data
was analyzed sex-wise. Azab and Abdel-Maksoud (1999) also reported
significant difference in Hb level during the early neonatal period.
However, Iriadam (2007) found no significant change in Hb concentration
in Kilis does.

Reduction in PCV values in in the present study is in concordance
to the previous studies (Vihan and Rai, 1987; Jain, 1993; Azab and
Abdel-Maksoud, 1999; Iriadam, 2007). Mean PCV percentage was low in male
animals which is in contrast to the findings obtained from Red Sokoto
Nigerian goats (Tambuwal et al., 2002) in which male animals have higher
PCV values than females. Mean values of corpuscular values (MCV, MCH,
MCHC) have their own significance in diagnosis of diseases and to
determine health status of flock. A significant decrease (p<0.001) in
all the studied corpuscular elements was observed which is in contrast
to the findings of Waziri et al. (2010). Mean values of corpuscular
elements can vary in different physiological stages, age groups and
breeds (Durotoye, 1987; Mbassa and Poulsen, 1991; Waziri et al., 2010).

A significant decrease in mean values of different performed
physiological and haematological parameters was noted in Kajli lambs
during the early neonatal period. Kajli sheep has been morphologically
and physiologically equipped to cope with extra-uterine environment and
relatively higher summer temperature effectively. Documentation of first
reference assessment to be published for the Kajli lambs would
definitely be helpful for the farm management and practitioners in the
diagnosis, treatments and management of diseases during the early phase
of life.